fluencelabs/wasm-bindgen
1
0
Fork 0
mirror of https://github.com/fluencelabs/wasm-bindgen synced 2025-03-16 02:00:51 +00:00
Code Issues Projects Releases Wiki Activity

Minor typo fixes and a few wasm links added

Browse Source
This commit is contained in:
Luke Wagner 2018-02-06 14:46:50 -06:00 committed by GitHub
parent aa90715896
commit 48db2f4b6e
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 10 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
DESIGN.md
View File

@ -15,7 +15,7 @@ JS files.
Now unfortunately at the time of this writing the interface of wasm interop
isn't very rich. Wasm modules can only call functions or export functions that
deal exclusively with `u32`, `u64`, `f32`, and `f64`. Bummer!
deal exclusively with `i32`, `i64`, `f32`, and `f64`. Bummer!
That's where this project comes in. The goal of `wasm-bindgen` is to enhance the
"ABI" of wasm modules with richer types like classes, JS objects, Rust structs,
@ -103,7 +103,7 @@ Here we can see a few notable points of action:
from the stack.
* Our exported function `foo`, takes an arbitrary argument, `arg0`, which is
converted to an index with the `addBorrowedObject` object function. The index
is the passed to wasm so wasm can operate with it.
is then passed to wasm so wasm can operate with it.
* Finally, we have a `finally` which frees the stack slow as it's no longer in
used, issuing a `pop` for what was pushed at the start of the function.
@ -113,6 +113,7 @@ there! Let's take a look at the code that `wasm_bindgen!` generates in Rust:
```rust
// what the user wrote
pub fn foo(a: &JsObject) {
// ...
}
#[export_name = "foo"]
@ -216,6 +217,7 @@ And finally, let's take a look at the Rust generated again too:
```rust
// what the user wrote
pub fn foo(a: JsObject) {
// ...
}
#[export_name = "foo"]
@ -341,9 +343,10 @@ happening:
and then we'll pass that ptr/length to wasm later on.
* Returning strings from wasm is a little tricky as we need to return a ptr/len
pair, but wasm only supports one return value. To work around this we're
actually returning a pointer to a ptr/len pair, and then using functions to
access the various fields.
pair, but wasm currently only supports one return value (multiple return values
[is being standardized](https://github.com/WebAssembly/design/issues/1146)).
To work around this in the meantime, we're actually returning a pointer to a
ptr/len pair, and then using functions to access the various fields.
* Some cleanup ends up happening in wasm. The `__wbindgen_boxed_str_free`
function is used to free the return value of `greet` after it's been decoded
@ -351,7 +354,7 @@ happening:
free the space we allocated to pass the string argument once the function call
is done.
At this point it may be preditable, but let's take a look at the Rust side of
At this point it may be predictable, but let's take a look at the Rust side of
things as well
```rust
@ -465,7 +468,7 @@ returned pointer.
## Exporting a struct to JS
So far we've covered JS objects, importing functions, and exporting functions.
This has given us quite a rich based to build on so far, and that's great! We
This has given us quite a rich base to build on so far, and that's great! We
sometimes, though, want to go even further and define a JS `class` in Rust. Or
in other words, we want to expose an object with methods from Rust to JS rather
than just importing/exporting free functions.